Rotary draw works brake



W. R. KELLEY ROTARY DRAW WORKS BRAKE 2 Sheets-Sheet 1 June 13, 1933.

Filed Sept. 22, 1930 *4 i a a 1 FIG. 3

WARD R. KELLEY IN ENTOR AT NE) June 13, 1933. w. R. KELLEY 1,913,333

ROTARY DRAW WORKS BRAKE Filed Sept.- 2, 1950 2 ShGG'tS-ShQet 2 FIG. 4

WARD R. KELLEY VENTOR Patented June 13, 1933 STATES VTARD R. KELLEY, OFLOS ANGELES, CALIFORNIA ROTARY DRAW WORKS BRAKE Application filedSeptember 22, 1930. Serial No. 483,658.

The prime object of my invention is to provide a brake suitable for theheavy duty and extreme wear encountered in the draw works of a rotary orother drilling rig.

An object of my invention is to so subdivide and mount the liningwithin'a brake band that any desired portion of the length of the liningmay be removed and replaced .without replacing the remainder. v

110 An object of my invention is to provide means for removing worn-outsections of the lining and for moving less worn sections into thepositions formerly occupied by the removed portions.

An object of my invention is to provide a brake lining which may easilyand cheaply be aflixed to interchangeable shoes and transported to thelocation at which said shoes Ware to be used.

In drilling oil wells the wire line on which casing and drill pipe areraised and lowered is woundon a reel to which is afiixed a brake drumcontrolled by brake bands. For lower- .-.ing and controlling a longstring of casing or pipe a very heavy drum is required and the bandlinings are'proportionately large and are subject to excessive wear.

Not only are these massive linings very costly in themselves, thehighest possible "grade of material being used, but also the labor andloss of drilling time involved in dismounting the band, removing andreplacing the worn lining and remounting the band are all sources ofundue expense.

Oil Well band brakes are uniformly constructed with one end fixed to astationary pin and the opposite end moved by a lever thus in Fig. 1 theloop A is pivoted on a fixed -pin while the loop B is moved by a handlever, not shown, in the direction indicated by the arrow B, to tightenthe band and apply the brake. Ordinarily the drum revolves within theband, while lowering, in the direction indicated by the arrow 0, or fromthe fixed end toward the free end of the band.

It will be evident that when the drum revolves in this direction whilebraking, that portion of the band adjacent the free end will bear on thedrum with much less force than will that portion of the band adjacentthe fixed end. The former is pressed against the drum only by the forceexerted through the hand lever while the latter is pressed against thedrum by an additional force due to the drag of the band on the drum. Inconsequencethe entering end of the band wears away its lining muchfaster than the parting end, and the former is usually entirely wornthrough before more than a third of the total mass of lining is wornaway. r In my improved design the brake lining is divided laterally intosections each of which is mounted on a block or shoe arranged to bemoved longitudinally on the band proper and to be retained atthe partingend (to- V ward which the shoes are urged by the friction of the drum)by abutment against the end loop or some other object attached to theend of the band. V In one modification of the invention each 76individual shoe may be removed from the inner side of the band; inanother modification removal is effected from an end of the band,

but in either modification it is possible to re- 'move any worn outsections, move less worn 5 sections into the positions formerly occupiedby those completely worn, and place new sections in the positionsformerly occupied by those least worn. This removal and transpositionmay be effected without removing the band fromits mounting, it beingonly necessary to slacken the band when the first modification is usedor to disconnect one loop when using the other.

By the use of my improved band great advantages may be realized:

A. It is possible to use compressed block lining which is much moredurable and less expensive than band lining but cannot be transported,in the sizes required for drawworks brakes, without breakage.

B. As shoes are removed only when the lining on such shoe is completelyworn out there is no wastage of unworn lining.

'0. As the shoes are gradually moved around the band from points of lesswear to v points of greater wear and new blocks inserted in thepositions formerly occupied by those least worn, the circle of lining iscon- 1..

stantly maintained in substantial conformity to the curvature of thedrum.

D. As only a small portion of the lining is renewed at any one time thetedious and often dangerous breaking in of new linings is avoided.

E. The labor incident to attaching the lining to a number of shoessufficient to line the band is much less than that incident to attachingstrip lining to the band itself, and this labor can be performed in aproperly equipped shop and the lined shoes taken to the rig instead ofmaking the renewal in the field.

l Distortion of the band by repeated removal and replacement and byrepeated attachment of new linings is entirely avoider.

G. The band, proper may be a continuous piece of steel of exactly thedesired flexibility and resilience and need not be weakened by.

bolt or rivet holes.

H. By making the shoes relatively short the band proper is permitted amuch greater flexibility than when relatively long lining sections areattached directly to the band.

Other objects and advantages of my invention will be evident oninspection of the attached drawings and the following descrip tionthereof, in which:

Fig. 1 is a side elevation of a complete band with shoes and liningsections in place;

Fig. 2'is a plan view of a part of the band seen from the outside,showing the method of attaching the shoes in one modification of myinvention Fig. 3 is a cross section on the line 33 of Fig. 2;

Fig. 4: is a plan view of a modified form of shoe;

Fig. 5 is a side elevation of the modification shown in Fig. 4, and

Fig. 6 is a cross section of the same modification on the line 66 ofFig. 5.

Referring to the drawings, 10 is a con- "tinuous band of flat steelformed to the curvature of the brake drum but of somewhat greaterdiameter. To the ends of this band are attached the loop 11 which passesaround a fired pin 12 and the loop 13 which passes around a leveractuated pin 14, this pin moving the free end of the band, in the usualmanner, in the direction indicated by arrow B, to tighten the band andits attached members against the drum.

If the type of lining shoe shown in Figs. 2 and 3 is used at least oneand preferably both of the loops must he readily detachable as by meansof the bolts 1515, but if the modification shown in Figs. 4, 5 and 6 isused the attachment of the loops may be permanent if so desired.

Within. this band and between the band and the drum I place a pluralityof shoes 16 to each of which is attached a block or strip of liningmaterial 17. The various manners of attaching brake lining to bands orshoes is well known and understood. In Fig. 5 I indicate flat headscrews 1818 without limiting myself to this or any other specific methodof attachment which, however, should be of such nature that the remainsof a worn lining may be removed and a new lining inserted in the shoewithout excessive labor.

Between the ends of the shoes I prefer to place filling strips orspacers 19 fitting loosely around the band and adapted to prevent theends of the shoes from chafing. The use of these filling strips isdesirable but not essential. The ends of the band must be pr0- videdwith some sort of projection to serve as an abutment for the end shoes.In Fig. 1 these abutments are shown as the ends 2020 of the straps fromwhich loops l1 and 13 are formed. Such number of shoes should be placedon the band as will almost but not quite occupy its length; the shoesmust not be so closely placed as to interfere with the free flexing ofthe band.

In the modification shown in Figs. 1 to 3 the shoe is retained on theband by means of lugs 21 extending over its edges. In this modificationthe shoe can be placed and removed only from an end of the band,requiring the removal of at least one of the loops 11 or 13.

In the modification shown in Figs. 4 and 6 the shoes may be placed frombelow or within the band, the side lugs 22 retaining the shoe againstside movement and the through bolts 23 holding it in place on the band.

In either modification a slight clearance in both directions should beallowed in order that the shoe may be moved longitudinally on the bandwithout binding, so that when a worn section is removed from one end theremainder of the shoes may be moved around the band for a correspondingdistance and a newly lined shoe placed at the opposite end to fill thespace thus formed. The upper face of the shoe in either form may beprovided with ribs as at 24 in order that nuts 25 may be placed on thelining attachment screws 18.

The objects and advantages of my invention will not be fully realized inany device in which. a worn section is removed and a freshly linedsection put into the space created by such removal, inasmuch as the newsection thus positioned would project materially beyond the curve formedby the uneven wearing of the lining, holding adjacent portions of-theband out of contact with the drum until the new section had been worndown to conform to the curvature of the remainder of the lining.

I claim as my invention:

1. A brake band for an externally contracting brake comprising aflexible metallic band having a loop member removably bolted to each endof the band in such a manner as to constitute an endwise stopfor thebrake lining, a plurality of shoes comprising metallic backing pieceshaving tWo or more pairs of lugs extending behind the band brake liningsections attached to the inner faces of said shoes, transverse openingsthrough each of said lugs and a bolt attached through the openings ineach opposite pair of lugs, said bolt extending across the back of saidband. 7 I

2. A brake band for an externally contracting brake comprising aflexible metallic band having a loop member attached to each end of theband in such a manner as to constitute an endwise stop for the brakel'in-. ing, a plurality of shoes comprising metallic backing pieceshaving two or more pairs of lugs extending behind the band, brake lining sections attached to the inner faces of said shoes, transverseopenmgs through each of said lugs and a bolt attached through theopenings in each opposite pair of lugs, said bolt extending across theback of said band. In witness that I claim the foregoing I have hereuntosubscribed my name this 16th day of September, 1930.

WARD R. KELLEYV

